Over the past 15 years, two-dimensional (2D) materials have been studied and exploited for many applications. In many cases, 2D materials are formed by the exfoliation of layered crystals such as transitionmetal disulfides. However, it has recently become clear that it is possible to exfoliate nonlayered materials so long as they have a nonisotropic bonding arrangement. Here, we report the synthesis of 2D-platelets from the earthabundant, nonlayered metal sulfide, iron pyrite (FeS2), using liquid-phase exfoliation. The resultant 2D platelets exhibit the same crystal structure as bulk pyrite but are surface passivated with a density of 14 × 1018 groups/m2. They form stable suspensions in common solvents and can be size-selected and liquid processed. Although the platelets have relatively low aspect ratios (∼5), this is in line with the anisotropic cleavage energy of bulk FeS2. We observe size-dependent changes to optical properties leading to spectroscopic metrics that can be used to estimate the dimensions of platelets. These platelets can be used to produce lithium ion battery anodes with capacities approaching 1000 mAh/g.
|Number of pages||15|
|State||Published - 27 Oct 2020|
Bibliographical noteFunding Information:
We acknowledge the European Union under grant agreements no 785219 Graphene Flagship-core 2 and the European Research Council Advanced Grant (FUTURE-PRINT). We have also received support from the Science Foundation Ireland (SFI) funded centre AMBER (SFI/12/RC/2278).
© 2020 American Chemical Society.
- Iron pyrite
- Liquid-phase exfoliation
- Lithium ion battery
- Nonlayered material
- Surface passivation